The subject matter disclosed herein relates to blade fold systems for aircraft.
Rotor-driven aircraft, for example, helicopters, utilize blade folding systems which fold the blades of a main rotor to reduce the space required for parking and/or storing the aircraft. Such systems are typically activated by an operator and visually monitored. Upon activation, each blade is to individually articulate from a spread position to a folded position. In a blade fold or blade spread, a number of events must happen in the proper sequence, for each blade and also among the blades. During operation, however, any number of faults in the system may prevent the blade folding sequence from occurring as required, and thus operates in an undesired sequence. At such times, it is desired to stop the blade folding sequence before a collision between the blades occurs to prevent costly damage to the blades. Detecting these faults, however, requires human observation and is therefore prone to human error and inattention, and further may be acting at a speed not easily perceptible by humans (either too fast or too slow).